Here's how it happened: We thought "What would go more perfectly with Justin's Daily Curios than a weekly puzzle from Thai?".
Answer: "A video of a tortoise eating mini-pancakes. But otherwise, absolutely nothing. Let's do a weekly puzzle from Thai."
So here we go again...
Using only common math operators and notation (and not searching the internet!), how can you use just four 7s to make 100? For example, you can use four 9s to make 100 like this: 99 + 9/9 = 100
Answer:
There are a few correct answers here; all the ones I've seen use our dear friend the decimal point.
- (7 * 7) / (.7 * .7)
- 77 / .77
- (77 - 7) / .7
- 7 / (.77 - .7)
Which means... wait for it... it works for any other digit (other than 0), too! Plug in 6s for all the 7s and it still works. So the Sevens aren't so lucky after all.
PS. You can see all of Thai's Teasers here.
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